I'm using OS X Lion, Python 2.7.2 built by Homebrew with llvm-gcc, and matplotlib installed via pip install git+git://github.com/matplotlib/matplotlib.git. There are no errors or other alarms during installation.

When I make an interactive figure with the Mac OSX backend the keyboard focus does not go to the plot window, it stays in the terminal. Mouse focus does go to the window. Clicking on the save button brings up the save dialog and I can click on things there, but typing just sends text to the terminal, making it impossible to specify a file name.

This seems to be the same as an issue reported on the ipython repo last year: ipython/ipython#1188 (I am not using ipython, though.)

If I switch to the Tkagg backend things work fine.